JPS6383473A - Piezoelectric driven valve and its driving method - Google Patents

Abstract

PURPOSE:To improve sealing performance in a long time closed state of a valve by fixing and supporting one end of a piezoelectric flexible element by a fixed member and bringing a fluid sealing valve element provided on the free end portion thereof into contact with the fluid outlet nozzle side. CONSTITUTION:One end portion of a piezoelectric flexible element 3 is fixed and supported by a fixed member 2 and a valve element 4 is provided on the free end portion of the element in a valve case 1. The valve case 1 is provided with a fluid outlet nozzle 6 positioned opposite to the valve element 4 to communicate with a fluid outlet port 7 through the nozzle 6. When pressure fluid is let flow in through a fluid inlet port 5 without a voltage applied, the pressure of the fluid starts to rise in the interior of the valve case 1, whereby the valve element 4 is strongly pressed to the fluid outlet nozzle 6 by the pressure of the fluid to seal the fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a piezoelectrically driven valve that utilizes deflection deformation of a piezoelectric flexure element due to voltage application, and a method for driving the same.

[Prior Art] Conventionally, a method using a piezoelectric body as a control valve in a fluid circuit, such as a pneumatic circuit or a hydraulic circuit, has been proposed.

For example, Utility Model Application Publication No. 175775 and Utility Model Application No. 60
Japanese Patent No. 75776 discloses a piezoelectric valve using a piezoelectric deflection element having a bimorph structure.

[Problem to be Solved by the Present Invention 1] In the piezoelectric valve using a bimorph piezoelectric deflection element disclosed in the above publication, the valve body closes the fluid inlet when no voltage is applied to the piezoelectric deflection element. ing. In order to sufficiently seal the fluid inlet with the valve body in this leap state, the piezoelectric deflection element is forcibly bent mechanically in advance, and the valve body is pressed against the fluid inlet.

In this way, in conventional piezoelectric valves, a considerable amount of elastic deformation has already occurred before voltage is applied to the piezoelectric deflection element, and in order to realize the open state of the fluid inlet, voltage is applied to the piezoelectric deflection element. This causes the piezoelectric plate to expand and contract, thereby further deforming the piezoelectric deflection element.

Ceramics are generally used as piezoelectric plates, but
Since ceramics has relatively low strength against tensile deformation, mechanical leap phenomenon is likely to occur in the convex piezoelectric plate due to elastic deformation, and for this reason, after a long period of time, the valve body is pressed against the fluid man 10. There was a problem that the sealing force was reduced, making it impossible to maintain a sufficient sealing state.

Furthermore, when the voltage applied to the piezoelectric deflection element is removed, the deflection deformation is immediately canceled due to the elastic recovery force of the piezoelectric deflection element itself, but a portion of the deflection deformation gradually occurs until the electric direction accumulated in the piezoelectric plate disappears. It has a tendency to be released. Such a delayed return operation is undesirable because it delays the operating speed when the valve is closed. To avoid this,
Conventionally, the structure was complicated, such as adding a short circuit to the drive circuit of the piezoelectrically driven valve.

[Means for solving the problem] As a method for solving the creep problem of the piezoelectric deflection element, the present inventors fix and support one end of the piezoelectric deflection element disposed inside the valve case with a fixing member, and, The fluid sealing block attached to the free end is placed so as to be in contact with the fluid outlet nozzle side, and is kept in a state where it is not subjected to any mechanical deformation.The force required for sealing is based on the force of the fluid itself. We have focused on the fact that by using pressure, the valve body can be reliably pressed against the fluid outlet nozzle and can maintain a sealed state for a long period of time, without any fear of creep occurring in the piezoelectric deflection element.

On the other hand, the pressing force F generated between the valve body and the fluid outlet nozzle due to the pressure fluid flowing into the valve case is given by the following equation, where d is the inner diameter of the fluid outlet nozzle and P is the pressure of the fluid. .

F=P・π(d/2)2 P=5 kg/c11! The F value when the inner diameter of the fluid outlet nozzle is changed is as follows.

F (g) d (dragon φ) 25 0.8 39 1.0 57 1.2 76 1.4 The flow rate of the fluid increases in proportion to the value of d, but on the other hand, the valve body is removed from the fluid outlet nozzle. The force required to release increases. The force generated when voltage is applied to the piezoelectric deflection element is used as the pulling force, but the force generated by the piezoelectric deflection element depends on the thickness of the piezoelectric plate, the vertical and horizontal size, the piezoelectric d31 constant, and the voltage.
Once each constant is determined, the generated force is also determined and the nozzle inner diameter cannot be increased arbitrarily. In order to solve the problem of flow rate and nozzle inner diameter, the present inventor has discovered the following method of driving a piezoelectric deflection element.

That is, a large force is required at the moment when the valve body is separated from the state where it is pressed against the fluid outlet nozzle by the pressure of the fluid.
- Once the valve body is separated, the pressure of the fluid is not applied, and it is understood that it is only necessary to secure a gap necessary for the movement of the fluid between the valve body and the fluid outlet nozzle. Furthermore, if the piezoelectric deflection element is a bimorph element, if a too high voltage is continuously applied in the direction opposite to the electric field during polarization, a depolarization phenomenon will occur in which the polarization is reversed, but if the piezoelectric deflection element is under an alternating electric field or only a short pulse voltage is applied By taking advantage of the property that depolarization is difficult to occur, a relatively high voltage is applied to the piezoelectric deflection element for a short period of time at the moment when the valve body is separated from the fluid outlet nozzle, and -
Once separated, depolarization is unlikely to occur even if voltage is applied for a long time, and the voltage is lowered to a level that provides enough displacement to secure the gap necessary for fluid flow between the valve body and the fluid outlet nozzle. It has been found that by applying a voltage, the nozzle can be kept open for a long period of time without performance deterioration due to depolarization.

The present invention is based on the above knowledge, and according to the present invention, (1) one end of the piezoelectric deflection element is fixed in a valve case by a fixing member, and a valve body is attached to the other end, which is a free end; The valve body is arranged so that its tip is in contact with the aε body nozzle whose tip is directed into the valve case, and the valve body is pressed against the fluid outlet nozzle by the pressure of the fluid flowing into the valve case from the fluid inlet port. A piezoelectric drive characterized in that the valve body is separated from the fluid outlet nozzle by the deflection deformation generated by applying a voltage to the piezoelectric deflection element, and the fluid flows out from the fluid outlet port. Valve mi (2) A valve that is divided into a main chamber and one or more sub-chambers by an airtight partition, and the main chamber has a fluid inlet port that penetrates the side wall and a fluid inlet port that penetrates the airtight partition to communicate the main chamber and the sub-chamber. A communication port is provided in the main chamber, and one end of the piezoelectric deflection element is fixed by a fixing member, and a valve body is attached to the other free end, and the valve body is attached to the communication port. The pressure of the fluid flowing into the main chamber of the valve from the fluid inlet port presses the valve body against the nozzle of the communication port to seal the fluid and apply a voltage to the piezoelectric deflection element. The structure is such that the valve body is separated from the nozzle of the communication port part by the deflection deformation caused by this, and the fluid flows out from the communication port to the auxiliary chamber. A fluid discharge nozzle is provided penetrating the side wall, one end of the piezoelectric deflection element is fixed by a fixing member in the subchamber, and a valve body is attached to the other free end,
The valve body is arranged so as to be in contact with the fluid discharge nozzle, and the pressure of the fluid flowing into the auxiliary chamber from the communication port with the main chamber presses the valve body against the fluid discharge nozzle, thereby sealing the fluid. The valve body is configured so that the fluid flows out from the port, and the valve body is separated from the fluid discharge nozzle by the deflection deformation generated by applying a voltage to the piezoelectric deflection element in the auxiliary chamber, thereby discharging the fluid. (3) One end of the piezoelectric deflection element is fixed in the valve case by a fixing member, and a valve body is attached to the other end which is a free end, and the tip of the valve body is directed into the valve case. The piezoelectric deflection element is placed in contact with a fluid outlet nozzle, and the pressure of the fluid flowing into the valve case from the fluid inlet port presses the valve body against the fluid outlet nozzle to seal the fluid, and a voltage is applied to the piezoelectric deflection element. In a piezoelectrically driven valve configured to separate the valve body from the fluid outlet nozzle and cause fluid to flow out from the fluid outlet port due to the deflection caused by the deflection, when voltage is applied to the piezoelectric deflection element to cause deflection deformation. As for the applied voltage, a high voltage is applied only for a short time when the valve body leaves the fluid outlet nozzle, and then the voltage is immediately switched to a low voltage where depolarization is unlikely to occur, and when the fluid is stopped, the voltage applied is (4) A method for driving a piezoelectrically driven valve, characterized in that the valve is operated by applying a voltage of opposite polarity for a short period of time, and (4) a valve that is divided into a main chamber and one or more auxiliary chambers by an airtight partition. The main chamber is provided with a fluid inlet port that penetrates the side wall and a communication port that penetrates the airtight partition wall and communicates the main chamber with the sub chamber. A valve body is attached to the other end which is fixed at the same time as the free end, and the valve body is arranged so as to be in contact with the nozzle attached to the communication port, and the fluid flowing into the main chamber of the valve from the fluid inlet port is fixed. The fluid is sealed by crimping the valve body to the nozzle of the communication port section with the pressure of The fluid is configured to flow out from the communication port to the auxiliary chamber, and the auxiliary chamber is provided with a fluid outlet port and a fluid discharge nozzle whose tip is directed into the auxiliary chamber, penetrating the side wall. One end of the piezoelectric deflection element is fixed by a fixing member, and a valve body is attached to the other free end, and the valve body is arranged so as to be in contact with a fluid discharge nozzle. The pressure of the fluid flowing into the chamber presses the valve body against the fluid discharge nozzle to seal the fluid, and at the same time allows the fluid to flow out from the fluid outlet port, and by applying a voltage to the piezoelectric deflection element in the auxiliary chamber. In a piezoelectrically driven valve characterized in that the valve body is separated from a fluid discharge nozzle and fluid is discharged by the generated deflection deformation, the deflection deformation is caused by applying a voltage to the piezoelectric deflection element in the main chamber. When stopping the fluid, apply a high voltage only for a short time when the valve body leaves the nozzle of the communication port, and then switch to a low voltage that makes it difficult to cause depolarization. A voltage of opposite polarity to the voltage initially applied is applied for a short period of time to the piezoelectric deflection element in the sub-chamber, and then a voltage of opposite polarity is applied to the piezoelectric deflection element of the main chamber, and then a voltage of opposite polarity is applied to the piezoelectric deflection element of the main chamber. A method of driving a piezoelectrically driven valve is provided, which is characterized in that the piezoelectrically driven valve is operated with the same voltage application pattern as the piezoelectric deflection element.

[Example] Specific examples of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a valve case, and one end portion of a piezoelectric deflection element 3 is fixedly supported within the case by a fixing member 2. As shown in FIG.

A valve body 4 is attached to the free end of a bimorph type piezoelectric deflection element 3 in which piezoelectric plates 31 are attached to both sides of a fully bent substrate 32. Although not shown in the figure, it goes without saying that the voltage application lead wire connected to the piezoelectric deflection element is insulated and hermetically sealed from the valve case 1 by an appropriate method. The valve body is made of a rubber material, for example. A fluid outlet nozzle 6 is provided in the valve case 1 at a position facing the valve body 4 , and the fluid outlet nozzle 6 communicates with a fluid outlet port 7 . The position of the valve body 4 is adjusted by a nozzle position adjustment mechanism 8 so that it contacts the tip of the fluid outlet nozzle 6. During adjustment, care must be taken not to cause excessive deflection deformation of the piezoelectric deflection element 3 itself.

During the inventory period when the piezoelectrically driven valve is left unenergized, the piezoelectric flexible element 3 is not subjected to mechanical deformation, so that no undesirable phenomena such as creep occur. When pressurized fluid is allowed to flow in from the fluid inlet bows 1-5 without applying any voltage, the pressure of the fluid begins to build up inside the valve case 1, and the valve body 4 of the piezoelectric deflection element 3 is forced into the fluid outlet nozzle 6 by the pressure of the fluid. Pressed to seal fluid. The higher the fluid pressure, the greater the sealing force to prevent fluid leakage. However, in the case of the present invention, the sealing force generated increases as the fluid pressure increases. The reliability of sealing is sufficient.

When EPT rubber is used as the valve body material and the fluid is N2 gas at a pressure of 5 kg/ctA, the amount of leakage is 4.5 m7 when it first flows into the valve case! /m
i n is below the allowable value specified in JISB8373 for electromagnetic valves.

FIG. 2 shows an example of a three-way valve. The valve is divided into two chambers, a main chamber 10A and a sub-chamber 10B, by an airtight partition 1b, and each chamber is connected by a communication port 11 leading from a nozzle 61 in the communication port section. Each room 10A, IOB
Inside, piezoelectric deflection elements 3 and 3b each having a valve body are arranged separately.

A voltage is applied to the piezoelectric deflection element 3 in the 10A chamber, and the valve body 4 is moved 1Zlf from the nozzle 61 of the communication port section to inject the fluid.
The fluid that flows into the IOB chamber from the A chamber via the communication port 11 flows out from the fluid outlet bow 1-7 provided on the side wall IC. At this time, the piezoelectric deflection element 3b for exhausting the chamber 10B is not energized. In order to close the nozzle 61 of the communication port 11, the voltage applied to the piezoelectric deflection element 3 is removed and the valve body 4 comes into contact with the nozzle 61 of the communication port, and then the piezoelectric deflection element 3b of the chamber 10B is energized. Then, the fluid discharge nozzle 6b is opened, and the fluid is discharged from the fluid discharge bow 19. A series of operations can be easily performed by the control circuit.

FIG. 3 shows an embodiment in which the cylinder is operated by a four-way valve. The valve case has three chambers 10A and IO due to the airtight partition wall 1b.
It is divided into B and 1'OC, and the main chamber 10Δ is equipped with a piezoelectric deflection element 3.3C, and the auxiliary chambers 10B and 10C are equipped with piezoelectric deflection elements 3b and 3d, respectively. There is.

There is a fluid discharge port 9, a fluid outlet port 7 on the side 11IC of the 10I3 chamber, a fluid discharge port 13 on the IOC chamber g, and a fluid discharge port 13 on the IC side. The cylinder 1G is connected by pipes 15a and 15b, and is for fluid [
-1 from port 7 to chamber 20a of cylinder 1G
The fluid port 1-13 is connected to the chamber 20b of the cylinder 1G by a joint 18.

To advance the cylinder head 19, a voltage is applied to the piezoelectric deflection elements 3 and 3d to cause deformation, and the cylinder head 19 is moved forward.
．． 4 (1) from the nozzle 61 of the communication port section and the fluid discharge nozzle 6d.The fluid flows from the inlet port 5 to the IOA of the valve.
The fluid flows into the chamber, passes through the nozzle 61 of the open communication port, passes through the communication port 11, and then flows from the fluid outlet port 7 to the pipe 1.
5a and flows into the chamber 20a of the cylinder 16. −
On the other hand, the fluid in the cylinder 201) chamber flows into the valve 1oc2 from the fluid outlet port 13 via the piping 15b, and escapes into the atmosphere from the open fluid exhaust port 14. Therefore, the cylinder head 19 moves forward.

To move the cylinder head 19 backward, a voltage is applied to the piezoelectric deflection elements 3b and 30 to connect the valve bodies 4b and 4c to the fluid discharge nozzle 6b, a part of the communication bow 1, and the nozzle 6 (, to the sho 1).
figure. No voltage is applied to the piezoelectric deflection element 7-3.3d.

The fluid in the IOA chamber of the valve passes through the nozzle 6C of the open communication port portion, flows into the IOC chamber through the communication port Ilb, and flows from the fluid outlet port 13 through the pipe 15b to the north of the chamber 20b of the cylinder 16. 2 of cylinder 16
The fluid in the 0a chamber flows into the IOB chamber of the valve via the pipe 15a, passes through the open fluid discharge nozzle 6b, and escapes to the atmosphere via the discharge port 9. Therefore, the cylinder head 19 moves backward.

By repeating this alternately, the cylinder head will reciprocate.

4 and 5 are diagrams showing a piezoelectrically driven valve characterized in that a valve body attached to a piezoelectric deflection element is pressed toward a fluid outlet by a spring material.

When a voltage is applied to a piezoelectric deflection element for a long time and then the voltage is removed, residual deflection deformation may occur in the piezoelectric deflection element. When residual deflection occurs, the problem is that the time it takes for the light body to press against the fluid outlet nozzle, communication port nozzle, fluid discharge nozzle, etc. becomes longer, or the pressing force weakens and fluid leaks occur. Become. In order to solve these problems, the piezoelectric deflection element is made of spring material 12 and/or
Alternatively, if you use 12b to lightly suspend the fluid in the direction of the fluid outlet nozzle and the fluid discharge nozzle in advance, and adjust the force of the spring so that even if residual deflection occurs, it will not remain. Various problems caused by thickening deformation can be solved.

6(A) to (rE) show voltage application patterns applied to the piezoelectric bending element.

FIG. 6(A) is a voltage application pattern for driving the piezoelectric valve shown in FIG. 1. In the first step, a high voltage is momentarily applied to the valve body 4 from one nozzle 6 for fluid.
μ is generated in the catahymorph-type piezoelectric element 3 due to the sealing force of the fluid pressing the .

- Once the valve body 4 has spilled out from the fluid outlet nozzle 6, no fluid pressure is applied to the valve body 4, and fluid flows between the valve body 4 and the outlet nozzle 6. Switch to a lower voltage that secures the necessary clearance (second step).

At this stage, the valve is open and fluid exits the fluid outlet port. When switching the valve to the closed state, a voltage of opposite polarity to that applied in the second step is applied to the piezoelectric deflection element (third step). By applying a voltage of opposite polarity for a short period of time, it is possible to reduce the delay in sealing operation of the valve body 4 and the amount of fluid leakage caused by residual deflection deformation that occurs when a voltage is applied to the piezoelectric deflection element for a long period of time. can.

The piezoelectric body is a titanate/lead zirconate based piezoelectric plate, 30 m long, 20 m3 thick, 0.2 u thick, with Ag electrodes attached to both sides, and a metal plate with a thickness of 0.1*s made with adhesive. EPT rubber with a thickness of 0.5 ml was attached to the free ends of the bimorph piezoelectric deflection elements attached to both sides of the valve body, and the valve body was placed in the valve case so that the fluid outlet nozzle was in contact with the free end. 100cm for 1 second as the first step,
70V is the voltage at which depolarization is unlikely to occur as a step.
, 6 hours, and in the third step, 170V was applied for 1 second. Using 5 kg/c++I nitrogen gas as the pressure fluid, the amount of nitrogen leaked after the second step and after the third step was measured over eight cycles.

The amount of nitrogen leaked after the second step was 4.5m1/
min, and the amount of nitrogen leaked after the third step is O, Om! ! /min, all of which satisfied the JIS standard, and especially when the third step reverse voltage was applied, the amount of nitrogen leakage disappeared.

FIG. 6(B) shows a voltage application pattern when driving the piezoelectric valve of FIG. 2. The piezoelectrically driven valve is divided into two chambers, and each nozzle is opened and closed by operating two piezoelectric flexure elements. The voltage application pattern for driving the piezoelectric deflection element 3 includes the first to third steps in the same manner as in FIG. 6
Add steps. It goes without saying that the time t for moving from the third step to the fourth step can be varied depending on the purpose.

FIGS. 6C and 6D show voltage application patterns for driving a piezoelectric valve characterized in that a valve body attached to a piezoelectric deflection element is pressed against a fluid outlet nozzle by a spring member. Figure 6 (C) is for the two-way valve shown in Figure 4.
FIG. 6(D) is a voltage application pattern for driving the piezoelectric valve for the three-way valve shown in FIG. 5, and FIG. 6(E) is a voltage application pattern for the four-way valve. When operating a valve having a structure in which a spring material is provided, there is a feature that there is no need to include a reverse voltage application process in the voltage application pattern when switching the valve state.

It is possible to operate with a control circuit in any voltage application pattern.

Figure 7 shows the piezoelectrically driven valve shown in Figure 1, the inner diameter of the fluid outlet nozzle is 0.8 x 1φ, and the input nitrogen gas pressure is 4 kg/c.
I]! , is a diagram showing the flow rate change behavior of nitrogen gas when 70 cm is continuously applied to the piezoelectric deflection element at a temperature of 25°C. It is clear that the gas flow rate remains constant even after 48 hours have elapsed, and there is no change in the flow rate even when the valve is open for a long time.

[Effects of the Invention] According to the present invention, by using the force exerted by fluid pressure on the valve body as the sealing force of the valve body, the necessary sealing force can be obtained at all times, even when the valve is closed for a long time. There is no increase in fluid leakage. Furthermore, a piezoelectric valve and a driving method are provided which ensure reliable operation by opening and closing the valve body and which make it possible to maintain the valve open state for a long time even at voltages where depolarization is difficult to occur.

In addition, as the pressing force required to seal the fluid outflow nozzle,
By using the pressure of the fluid itself, when the voltage is removed from the piezoelectric deflection element, the elastic recovery force of the piezoelectric deflection element causes the pressure of the fluid to suddenly apply to the valve body from the position where the valve body is almost close to the tip of the fluid outlet nozzle. As the valve starts to act, there is no response delay related to charge release, and the pressure of the fluid ensures that the valve body comes into close contact with the fluid outlet nozzle, which prevents the hunting phenomenon caused by vibration of the valve body, and there is no need to provide a short circuit. There are no advantages.

[Brief explanation of the drawing]

1, 2, 3, 4 and 5 are schematic diagrams showing piezoelectrically driven valves of the present invention. FIGS. 6(A) to 6(E) are diagrams showing patterns of voltage application to a piezoelectric deflection element, which is a method for driving a piezoelectrically driven valve according to the present invention. FIG. 7 is a diagram showing the flow rate change behavior of nitrogen gas when 70 V is continuously applied to the piezoelectric deflection element in the piezoelectrically driven valve of FIG. 1. 1: Valve case 1b
: Airtight bulkhead IC-side wall 2 : Fixing members 3.3b, 3c, 3d: Piezoelectric deflection elements 4.4b, 4c
, 4d: Valve body 5: Fluid inlet port 6
: Fluid outlet nozzle 61.6C: Nozzle 6b, 6d of communication port part: Fluid discharge nozzle 7.13
:m rest report 8
: Nozzle position adjustment mechanism 9.14 : Fluid discharge port 10A : Main chamber 10B, 10C: Sub-chamber 11. llb: Communication port 12.12b: Spring material 15a, 15b: Piping 16 Niji cylinder 17.18: Joint 19 Niji cylinder head 20a, 20b
Niji Linda Inner Branch Patent Applicant Ube Industries Co., Ltd. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 (Zone 1) Figure 6 (Part 3) (E) Figure 7 Time (min') 1

Claims (5)

[Claims] (1) One end of the piezoelectric deflection element is fixed in the valve case by a fixing member, and a valve body is attached to the other free end, and the valve body is attached to a fluid outlet nozzle whose tip is directed into the valve case. The valve body is placed in contact with the fluid outlet nozzle by the pressure of the fluid flowing into the valve case from the fluid inlet port, thereby sealing the fluid, and the deflection generated by applying a voltage to the piezoelectric deflection element. A piezoelectrically driven valve characterized in that the valve body is separated from a fluid outlet nozzle by deformation, and fluid flows out from a fluid outlet port. (2) A valve that is divided into a main chamber and one or more auxiliary chambers by an airtight partition, and the main chamber has a fluid inlet port that penetrates the side wall and a communication port that penetrates the airtight partition and communicates the main chamber and the auxiliary chamber. A port is provided, and one end of the piezoelectric deflection element is fixed by a fixing member in the main chamber, and a valve body is attached to the other free end, and the valve body is connected to a nozzle attached to the communication port. The pressure of the fluid flowing into the main chamber of the valve from the fluid inlet port presses the valve body against the nozzle of the communication port to seal the fluid and apply a voltage to the piezoelectric deflection element. The structure is such that the valve body is separated from the nozzle of the communication port part by the deflection deformation caused by the flow, and the fluid flows out from the communication port to the subchamber, and the subchamber has a fluid outlet port and a tip facing into the subchamber A fluid discharge nozzle is provided passing through the side wall, one end of the piezoelectric deflection element is fixed by a fixing member in the subchamber, and a valve body is attached to the other free end,
The valve body is arranged so as to be in contact with the fluid discharge nozzle, and the pressure of the fluid flowing into the auxiliary chamber from the communication port with the main chamber presses the valve body against the fluid discharge nozzle, thereby sealing the fluid. The valve body is configured so that the fluid flows out from the port, and the valve body is separated from the fluid discharge nozzle by the deflection deformation generated by applying a voltage to the piezoelectric deflection element in the auxiliary chamber, thereby discharging the fluid. piezoelectrically driven valve. (3) Claims 1 and 2, characterized in that the valve body attached to the piezoelectric deflection element is pressed against the fluid outlet nozzle and/or the fluid discharge nozzle by a spring material.
Piezoelectrically driven valve. (4) One end of the piezoelectric deflection element is fixed in the valve case by a fixing member, and a valve body is attached to the other free end, and the valve body is attached to a fluid outlet nozzle whose tip is directed into the valve case. The valve body is placed in contact with the fluid outlet nozzle by the pressure of the fluid flowing into the valve case from the fluid inlet port, thereby sealing the fluid, and the deflection generated by applying a voltage to the piezoelectric deflection element. In a piezoelectrically driven valve configured to separate the valve body from the fluid outlet nozzle by deformation and cause fluid to flow out from the fluid outlet port, when a voltage is applied to the piezoelectric deflection element to cause deflection deformation, the voltage applied to the valve is Apply a high voltage only for a short time when the body leaves the fluid outlet nozzle, then immediately switch to a lower voltage that is less likely to cause depolarization, and when stopping the fluid, apply a voltage with the opposite polarity to the initially applied voltage. A method for driving a piezoelectrically driven valve, characterized in that the piezoelectrically driven valve is operated by applying a voltage for only a short period of time. (5) A valve that is divided into a main chamber and one or more auxiliary chambers by an airtight partition, and the main chamber has a fluid inlet port that penetrates the side wall and a communication port that penetrates the airtight partition and communicates the main chamber and the auxiliary chamber. A port is provided, and one end of the piezoelectric deflection element is fixed by a fixing member in the main chamber, and a valve body is attached to the other free end, and the valve body is connected to a nozzle attached to the communication port. The pressure of the fluid flowing into the main chamber of the valve from the fluid inlet port presses the valve body against the nozzle of the communication port to seal the fluid and apply voltage to the piezoelectric deflection element in the main chamber. The structure is such that the valve body is separated from the nozzle of the communication port part by the deflection deformation caused by this, and the fluid flows out from the communication port to the auxiliary chamber. A fluid discharge nozzle is provided to pass through the side wall, and one end of the piezoelectric deflection element is fixed by a fixing member in the subchamber, and a valve body is attached to the other end, which is a free end. is placed in contact with the fluid discharge nozzle,
The pressure of the fluid flowing into the auxiliary chamber from the communication port with the main chamber presses the valve body against the fluid discharge nozzle to seal the fluid, and also allows the fluid to flow out from the fluid outlet port, reducing piezoelectric deflection in the auxiliary chamber. A piezoelectrically driven valve characterized in that the valve body is separated from a fluid discharge nozzle and fluid is discharged by the deflection deformation generated by applying a voltage to the element. When applying deflection deformation,
The magnitude of the applied voltage is such that a high voltage is applied only for a short time when the valve body leaves the nozzle of the communication port part, and then the voltage is immediately switched to a low voltage at which depolarization is unlikely to occur.
When stopping the fluid, a voltage with the opposite polarity to the voltage initially applied was applied for a short period of time, and a voltage of opposite polarity was applied to the piezoelectric flexure element in the main chamber to the piezoelectric flexure element in the auxiliary chamber. A method for driving a piezoelectrically driven valve, characterized in that the piezoelectrically driven valve is later operated with the same voltage application pattern as in the case of the piezoelectric deflection element in the main chamber.